SummaryAscaris lumbricoides is the most common intestinal parasite to infect humans. The incidence of ascariasis is increasing in our regions, due to world travel and population migration. In one third of cases, the worm can enter the bile duct and cause cholangitis or biliary colics. Diagnosis and treatment of ascariasis are discussed. Endoscopic retrograde cholangio-pancreaticography (ERCP) with endoscopic extraction of the worm, using a Dormia basket, is a safe and effective procedure for the diagnosis and treatment of biliary ascariasis. This technique serves as an effective alternative for surgery.